Core clamping means



Jan. 18, 1949a E. F. GooDRxcH 2 Sheets-Sheet l \NVENTOB may;

Jan. 18, 1949. E F, GOQDRICH 2,459,374 CORE CLAMPING MEANS Filed D90. 25, 1946 2 Sheets-Sheet 2 11| 3 I MMIII". r /0 Uf v IIH'H' 'I 8W. f' 1| a? 5 MH "M lpg. IMI

1. l vlc?. 7 'Hill- I Qi@ I (((Km um )WE/) rg/ Nif' f! \NvENToR 5 I EARL F.' QooomcH @l Q mm om TToRNaYs x cuculcu Jau. lo, 12HR! UNITED STATES PATENT OFFICE CORE CLAMPING MEANS Earl F. Goodrich, Grand Rapids, Mich., assignor to Kirkhof Manufacturing Corporation, Grand Rapids, Mich.. a corporation of Michigan Application December 23, 1946, Serial No. 717,949

2 Claims.

This invention is in connection with electrical transformers, by means of which a current is transformed into one of lower voltage and higher amperage than the one entering the transformer. Such transformers, in general, are old and well known, and the present invention is directed to novel improvements in structure and assembly of the transformer cores and windings using novel means for maintaining them at allv times in secure and operative relation to each other, and avoiding any decrease in elciency under the varying conditions of transformer operation as when the transformer is subject to temperature changes and, at times, to relatively high increases in temperature with the consequent expansion of the transformer parts.

With my invention a very practical, simple, sturdy and eiective means is used for holding and maintaining the transformer parts in their proper relation to each other such that eiiiciency is not reduced but is maintained substantially constant under all operating conditions.

An understanding of the invention may be had from the following description, taken in connection with the accompanying drawings, in which Fig. 1 is a vertical section through the transformer substantially on the plane of line I--I of Fig. 2.

Fig, 2 is a horizontal section on the plane of line 2 2 of Fig. 1, and

Fig. 3 is a perspective view showing transformer core and the novel holding and securing means therefor used, in a disassembled condition.

Like reference characters refer to like parts in the different figures of the drawings.

In the structure shown, the transformer high current carrying windings I alternating with the low current windings 2 which, in practice, are of solid structure, are enclosed by insulating walls 3 and separated by like walls. The windings, in accordance with general practice, are of a generally rectangular open character. With them are associated transformer cores each in two parts indicated at l and 5. Each of the transformer core parts 4 and 5 are U-shaped and are located with their ends together (Fig. 2) in the transformer located around the vertical sides of the windings I and 2.

As shown in Figs. 1 and 2 there are four of the transformer cores disclosed, each of the two parts 4 and 5. They are disposed in two horizontal series and one over the other (Fig. 1), and each of the horizontal series includes two complete cores located in horizontal side by side rela- 2 tion. The windings have the usual wire connections at 6 for the h igh and low voltage currents.

Fach of the two series of horizontally disposed cores are held and maintained in proper relation to each other, with the ends of the legs of the U-shaped core parts 4 and 5 in engagement, by two thin hexible metal bands formed into a generally rectangular shape, the ends of the bands l overlapping and being welded together. Said bands, at opposite sides thereof, are pressed in wardly providing substantially V-shaped inwardly extending vertically recessed portions l. The bands are generally shaped to conform to the outer surfaces of the assembled core parts 4 and 5 and may be placed therearound, two of them extending around the two complete cores located in the same horizontal plane. Said bands used (Fig. 1) are vertically spaced a short distance apart in each of the pairs thereof.

A flat bar 9 of metal, at each end, is formed with a rodlike extension externally threaded. Two short vertical rods I0 are seated in the inwardly pressed portions 8, one at one side and one at the other of each of the pairs of bands, and the threaded end portions of the bar 9 pass through the rods I0 midway between their ends and receive nuts II. By tightening the nuts, the bands may be brought into the desired contact engagement against the outer parts of the core parts 4 and 5 holding them securely together and against change of position with respect to each other or to the windings with which associated.

In tightening the nuts I I in the assembly, it is done by means of a wrench supplied with a mechanism and an indicating dial therefor which will Inform the workman of the force exerted in tightening the nut. Such tightening is not to go beyond a certain predetermined force indication in order that provision may be made for the expansion of the cores under rising temperatures. Therefore, the bands are not initially tightened upon the cores to the fullest possible degree and extent but are tightened suiliciently to bring the bands against the sides of the cores, but with a sulcient leeway left at the recesses at 8 for the core expansion without unduly straining the bands. The cores, accordingly, remain in a permanent relationship to each other and do not change position substantially relative to the transformer housing, and the emciency of the transformer is not impaired but remains substantially constant.

The transformer as described, has proven very '-'The' invention is practical and useful and is ot a simple and sturdy structure. easily manufactured and assembled.

defined in the appended claims and is to be considered comprehensive of all forms ot structure coming within their scope.

I claim:

1. In a transformer structure including two cotes located side by side. each of said cores being divided between its ends, the ends of said cores at adiacent sides being rounded to form outwardly opening recesses, two strong exible bands extending completely around both ot said cores in spaced relation, a bolt extending between said cores and having a threaded and and a nut thereon, and a. rod located at each of the ends of said cores within said recesses, each rod extending between and engaging said bands and said rods being engageable with said bolt at opposite ends thereof, whereby manipulation of The following references EARL 1|'. GOODRICH. REFERENCES CITED areotrecordinthe 10 ie of this Potent:

UNITED STATES PATENTS Number 

